The present invention relates to an oxygen-conserving regulator assembly, and particularly to an oxygen-conserving regulator assembly for use with a high-pressure oxygen system. More particularly, the present invention relates to a modular oxygen-conserving regulator assembly and to an integrated pressure regulator, oxygen-flow control valve, and pneumatic demand oxygen valve assembly.
Supplemental oxygen-delivery systems are provided to administer medicinal gas, normally oxygen, to a patient undergoing respiratory therapy. Supplemental oxygen-delivery systems are used by patients that benefit from receiving and breathing oxygen from an oxygen supply source to supplement atmospheric oxygen breathed by the patients. A compact, portable supplemental oxygen-delivery system is useful in a wide variety of contexts, including hospital, home care, and ambulatory settings.
High-pressure supplemental oxygen-delivery systems typically include a cylinder or tank containing oxygen gas at a pressure of up to 3000 psig. A pressure regulator is used in a high-pressure oxygen-delivery system to "step down" the pressure of oxygen gas in the tank to a lower pressure level (e.g., 20 or 50 psig) suitable for use in an oxygen-delivery apparatus used by a patient in respiratory therapy.
The COMPANION.RTM. high-pressure portable oxygen systems available from Nellcor Puritan Bennett Incorporated, Cryogenic Equipment Division, Indianapolis, Ind., USA, include a COMPANIONS 360.RTM. regulator/flow controller unit Model No. 77231. This regulator/flow controller unit can be coupled to a high-pressure oxygen gas tank. This regulator/flow controller unit does not include a pneumatic demand valve.
A breathing assist apparatus including a flow controller and a pneumatic demand valve is disclosed in
U.S. Pat. No. 5,360,000 to Carter. A flow controller is included in the breathing assist apparatus to meter the flow rate of low-pressure oxygen (typically in liters per minute) delivered to the patient. A pneumatic demand valve is included in the breathing assist apparatus to distribute oxygen to a patient only when oxygen is "demanded" by the patient during inhalation and thus functions to "conserve" oxygen by not distributing oxygen to an exhaling patient. A demand valve delivers a pulse of oxygen at the onset of patient inspiration and continues to deliver oxygen throughout the entire patient inspiration. These demand valves do not deliver oxygen to the patient as the patient exhales.
Pneumatic demand oxygen valves are available from Nellcor Puritan Bennett Incorporated. For example, the COMPANION.RTM. 550 is a small lightweight portable liquid oxygen unit with a built-in demand valve and flow controller. A liquid oxygen unit contains liquid oxygen in a reservoir and is very different from a high-pressure oxygen gas cylinder or tank oxygen-delivery system.
What is needed is an oxygen-conserving regulator assembly that is modular and includes a pressure regulator, an oxygen-flow controller, and a pneumatic demand oxygen valve. Consumers would welcome a modular unit that could be reconfigured easily by replacing one modular component such as, for example, the flow controller or the pneumatic demand oxygen valve with another modular component to adapt the modular unit to current needs of a patient.
What is further needed is an integrated pneumatic demand oxygen valve and regulator assembly that is suitable for use with a high-pressure oxygen gas system. Integration of a pneumatic demand oxygen valve in a high-pressure oxygen-delivery system including a pressure regulator, and perhaps also an oxygen-flow controller, would provide a patient using a high-pressure oxygen gas system with the benefits of a pneumatic demand oxygen valve.
What is also needed is an oxygen-flow controller that is operable to provide oxygen to a patient either continuously or on patient demand without requiring a patient to operate a separate continuous/demand oxygen flow selector switch mounted on a separate demand-type pneumatic oxygen valve in the conventional way. Patients would appreciate the ease of using a continuous/demand selector switch integrated in an oxygen-flow controller.
According to the present invention, an apparatus is provided for controlling discharge of oxygen from an oxygen supply source to a patient. The apparatus includes an pressure regulator module, a flow controller module coupled to one side of pressure regulator module, and a pneumatic demand valve module coupled to another side of pressure regulator module. Oxygen is constrained to flow from the oxygen supply along a path to a patient through, in sequence, pressure regulator module, flow controller module, and pneumatic demand valve module.
In preferred embodiments, flow controller module includes an internal chamber for receiving oxygen discharged by the pressure regulator module and a flow control valve positioned to split the flow of oxygen discharged from the internal chamber into a first oxygen stream and a second oxygen stream. The first oxygen stream is conducted along a patient supply conduit through the pressure regulator module and the pneumatic demand valve module to reach a breathing cannula worn by a patient. The second oxygen stream is conducted along an auxiliary conduit through the pressure regulator module to reach and control a valve positioned in the pneumatic demand valve module and pneumatically coupled to an inhale/exhale sensing diaphragm also positioned in the pneumatic demand valve. The flow control valve is a rotary valve that extends into the internal chamber and can be rotated about an axis to adjust flow controller module to operate in either "demand" mode, "continuous" mode, or "off" mode. The flow control valve is movable between a first position range discharging oxygen from the internal chamber into both of the patient supply and auxiliary conduits, a second position range discharging oxygen from the internal chamber into only the patient supply conduit, and a third position range blocking flow of oxygen from the internal chamber into the patient supply and auxiliary conduits.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.